Just last week we did a little birding with WBU's Chief Naturalist John Schaust. We saw a Magnolia Warbler gleaning insects from leaves and he pointed out a very distinctive field mark: a white band in the tail.
On the Confusing Fall Warbler page of the Peterson Field Guide this is pointed out, as is the yellow rump. I vowed to keep these key field marks in mind when viewing warblers.
Low and behold, just 5 days later, I had my chance. My first look at the bird was typical warbler - partially obstructed. My second look was much better.
But my next look sealed it: a beautiful white band at midtail. Add the yellow rump and I had myself a Magnolia Warbler! No need to even check the guide or ask around (which doesn't happen often for me!!)
Another useful page in the Warblers Peterson Field Guide is the undertail pattern page that also shows a dark outer band and white inner band and undertail coverts. I got a good look at those too.
It doesn't happen often with warblers, but it's nice to have such distinctive field marks on a bird to solidify an ID. It's also nice to be able to put a tip into practice right away, to help cement in my little brain!! I need all the help I can get with warblers!